Ayat 37. Musa PBUH (Moses) said: "My Lord knows best him who came with guidance from Him, and whose will be the happy end in the Hereafter. Verily, the Zalimun (wrong-doers, polytheists and disbelievers in the Oneness of Allah) will not be successful."

Tafseer of Surah Al-Qasas (The Narration) Ayat 37. Moses said: "My Lord knows best who it is that comes with guidance from Him and whose end will be best in the Hereafter: certain it is that the wrongdoers will not prosper." The only argument in such a case is an appeal to Allah and to the ultimate Future. Both of these appeals require Faith. But even if you do not rely on anything so high, you can see that Falsehood or evils crystallized in ancestral customs are not going to do anyone any good.